JPH05345205A - Self-starting type generating tool - Google Patents

Abstract

PURPOSE: To provide a mechanism for moving a rotary cutter element in the axial direction in the interior of a rotary spindle. CONSTITUTION: A cutter element 12 is attached to a slider 14 capable of moving in the direction of crossing a spindle shaft 15 of a rotary spindle to be thereby moved to the interior of the rotary spindle or to the outside therefrom. A pulling rod 17 capable of moving in the axial direction is positioned in the interior of the rotary spindle to move the cutter element. The pulling rod is connected to the slider 14 so that when the pulling rod is moved to the right side in the drawing, the cutter element is drawn in, and when it is moved to the left in the drawing, the cutter element is brought to its working position. The pulling rod is slidable in the axial direction to the rotary spindle 10, but no rotatable relatively to the rotary spindle 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machining tool including a rotary spindle having a radially movable cutter means at one end thereof. An axially slidable pull rod is disposed within the rotary spindle for moving the cutter means radially into the rotary spindle.

[0002]

BACKGROUND OF THE INVENTION There are various conventional devices associated with rotating spindles for moving a cutter between an extended operating position and a retracted position. US Patent 33915
No. 85 shows a double-acting hydraulic cylinder for this purpose. U.S. Pat. No. 3,740,161 also shows a double-acting hydraulic cylinder for retracting the cutter. U.S. Pat. No. 4,742,738 shows a planetary gear mechanism for retracting a cutter element carried on a rotating spindle. The use of harmonic drive means for retracting the rotary cutter element is considered novel in the prior art.

[0003]

SUMMARY OF THE INVENTION It is an object of the invention to provide a mechanism for axially moving a rotary cutter element within a rotary spindle.

[0004]

SUMMARY OF THE INVENTION In accordance with the present invention, a mechanism is provided for axially moving a drawbar within a rotating spindle. This mechanism includes a harmonic drive means which is carried on the rotary spindle and which is normally immovable, and a cam which connects the harmonic drive means and the pull rod. It can be activated in the axial direction. The harmonic drive means is activated by the braking means arranged to engage the reaction member therein. The braking means can be actuated by an electric or hydraulic signal generated at a remote location.

[0005]

1 shows a working tool carrying a retractable cutter element 12 and including a power-driven rotary spindle 10. The cutter element 12 is attached to a slide 14 which is movable in a direction transverse to the spindle axis 15 of the rotary spindle, so that the cutter element can be moved in or out of the rotary spindle. An axially movable drawbar 17 is positioned inside the rotary spindle for moving the cutter element. The pull rod is connected to the slide body 14 so that the cutter element is retracted when the pull rod moves to the right in FIG. 1 and brought to its operating position when it moves to the left in FIG. To be done. The end portion of the pull rod is bifurcated, and the inclined tip end portion thereof functions as a cam for moving the sliding body. FIG. 1 shows the drawbar in a position in which the cutter element extends from the rotating spindle. The drawbar is axially slidable with respect to the rotary spindle 10, but is not rotatable relative to the rotary spindle. The key 19 extends from the drawbar into the axial slot 21 in the rotary spindle to prevent relative rotation between the drawbar and the rotary spindle.

The illustrated machining tool is axially aligned 2
It includes two members 23 and 25. Bolts 27 may be used to connect these two members. The two-part rotary spindle comprises anti-friction bearings 30 and 3
It is rotatably supported in a stationary annular housing 29 which carries 1. The annular housing 29 also carries releasable braking means 33 which control the operation of the harmonic drive means carried on the rotary spindle. The harmonic drive means includes an annular reaction member 35. The annular recoil member 35 includes a toothed inner surface 37 and an outer surface 39 for engaging the braking means.
Have. The annular input means to the harmonic drive means is constituted by two rollers 41 extending axially from the shoulder 43 of the rotary spindle into the space circumscribed by an annular deformable band (ring) 45. The annular deformable band 45 constitutes an annular output means for the harmonic drive means. Those skilled in the art will recognize that a bearing may be added between the deformable band 45 and the annular reaction member 35 and modifications may be made to further increase the drive speed and reduce friction of the harmonic drive means. .. Furthermore, the harmonic drive means could be replaced with other gear arrangements for reduction without departing from the scope of the invention.

During normal use of the working tool, the harmonic drive means is immobilized. The working parts of the harmonic drive means (annular reaction member 35, two rollers 41, deformable band 45) rotate together with the rotary spindle as one unit. An annular cam element 47 is supported on the rotating spindle and is loosely linked to the deformable band 45. The illustrated linkage includes a series of axial slots 49 in the deformable band 45 and matching ribs (sprockets) 51 extending radially outwardly from the annular cam element 47 into the axial slots. included. The linkage is such that the annular cam element 47 is always rotated with the deformable band 45, but the deformable band is radially deformable with respect to the annular cam element.
The end surface 53 on the left side in FIG. 1 of the annular cam element 47 is steeply angled with respect to its radial plane, thereby forming an axially extending cam surface. A flat radial plate 55, preferably secured to the drawbar 17, operatively engages the cam surface 53. A coil spring 57 acts on the drawbar 17 to maintain the radial plate 55 and the annular cam element 47 in operative engagement. The radial plate 55 acts as a cam follower. The braking means 33 mentioned above comprises a solenoid 59 having a plunger 61 extending towards the outer surface 39 of the reaction member 35.
including. During normal operation, this plunger 61 is spaced from the reaction member 35 as shown in FIGS.
When attempting to move the cutter element 12 towards and away from the rotary spindle, the solenoid 59 is operated remotely to bring the plunger 61 into engagement with the reaction member 35, thereby stopping (braking) the reaction member. Hold the state. The end portion of the plunger 61 has a chisel shape for facilitating entry into the outer surface 39.

When the recoil member 35 is at rest, the deformable band 45 rotates relatively slowly on the recoil member 35. The roller 41 rotates (rotates on the orbit) at a speed proportional to the speed of the rotary spindle 10, thereby meshing the deformable band 45 with the stationary reaction member 35.
The deformable band 45 has a smaller number of teeth than the reaction member 35, so that the deformable band 45 is slowly rotated in the direction opposite to the rotating spindle 10. This movement is relative, not absolute.
The annular cam element 47 rotates with the deformable band 45,
1. Axial movement of the pull rod 17 to the right in FIG.
generate. The pull rod follows the end face and the cutter element 1
2 is moved away from and towards the rotary spindle, thereby defining one complete cycle of rotary cutter work. After the drawbar 17 has moved a predetermined distance to the right in FIG. 1, the shoulder 63 of the drawbar 17 is positioned slightly to the right of the actuator element of the switch 65 in FIG. This actuates the switch from one state to another. The switch 65 is electrically positioned in the control circuit for the solenoid 59 and when the switch is toggled the solenoid is activated and the plunger 6
1 is separated from the reaction member 35. Thus, the reaction member returns to its normal rotating state (the state of rotating with the rotating spindle). Upon such actuation, the annular cam element 47 is returned to the retracted condition and the drawbar is moved to its normal inactive or neutral position.

The illustrated harmonic drive means has the advantage that it uses the movement of the rotating spindle as the drive source and does not require any external drive force. The harmonic drive means further has the advantage of being relatively compact and being able to be incorporated inside the rotary spindle without any increase in spindle diameter or spindle length.
In the figure, the braking means are shown in the form of a plunger actuated by an electric solenoid. Alternatively, the plunger can be hydraulically actuated. That is, the plunger may be part of a hydraulic piston which may be connected to a remotely located hydraulic source. It should be noted that various other changes can be made in carrying out the invention.

[0010]

A mechanism is provided for axially moving a rotary cutter element within a rotary spindle.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a specific example of a working tool of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

[Explanation of symbols]

 10: Rotating spindle 12: Cutter element 14: Sliding body 17: Pull rod 19: Key 29: Annular housing 30: Anti-friction bearing 31: Anti-friction bearing 33: Braking means 35: Reaction member 45: Deformable band 47: annular cam element 55: radial plate 59: solenoid 61: plunger

Claims (8)

[Claims] 1. A rotary spindle, a cutter means carried by the rotary spindle and movable in a radial direction, a pull rod positioned inside the rotary spindle and slidable in the axial direction, the pull rod and the cutter means. Mutual coupling so that axial movement of the drawbar within the rotary spindle causes the cutter means to move radially into or out of the rotary spindle. Means, the harmonic drive means carried on the rotary spindle and normally inactive, the harmonic drive means including an annular input means, an annular reaction member, and an annular output means; and the annular reaction member. Releasable brake means movable towards or away from it and between the annular output means and the pull rod, thereby connecting the annular means. A machining tool constituted by an output means for axially driving a pull rod so as to retract the cutter means. 2. The machining tool according to claim 1, wherein the annular reaction member has an inner surface provided with teeth and an outer surface for engaging the releasable braking means. 3. The machining tool of claim 2 wherein the releasable braking means includes a solenoid having a plunger movable toward or away from the outer surface of the annular reaction member. 4. The machining tool according to claim 1, wherein the annular reaction member at least partially surrounds the annular input means and the annular output means. 5. The cam coupling includes a plate extending radially from the drawbar and an annular cam member having a cam surface axially aligned with the plate, thereby providing rotational movement of the cam member. A machining tool according to claim 1, wherein said plate and associated drawbar are adapted to be moved axially. 6. A fixed annular housing surrounding the rotating spindle and an axially spaced anti-friction bearing carried by the annular housing and rotatably supporting the rotating spindle. Processing tool. 7. The machining tool of claim 6 wherein the releasable braking means includes a radially movable plunger mechanism carried between anti-friction bearings of the annular housing. 8. The releasable braking means comprises a solenoid carried by an annular housing and having a plunger movable toward or away from the annular reaction member. Item 6 processing tool.